Urethroscrotal fistula complicating large spermatocele in a male ketamine abuser: A case report

Ketamine related urinary tract complications were first reported in Hong Kong since 2007. The current case report describes a 37 years old male with long history of ketamine abuse, renal impairment, hypertension and HCV hepatitis, presented to us with insidious onset of painful scrotal swelling post bilateral nephrectomy, prostate and seminal vesicle preserving cystectomy. Radiological imaging and intraoperative finding revealed that it was a large spermatocele with urethroscrotal fistula, which was likely due to urethra stricture. The review of literature showed no guidelines for treatment, a symptoms based and multidisciplinary team approach is recommended.

Initial experience of cryoballoon catheter ablation for atrial fibrillation in Hong Kong

OBJECTIVE. To report the initial experience in using cryoballoon catheter ablation in the treatment of atrial fibrillation in Hong Kong. DESIGN. Single-centre, prospective case series. SETTING. Regional hospital, Hong Kong. PATIENTS. Sixteen patients (mean age, 55 years; standard deviation, 14 years; 11 males) with paroxysmal (n=12) or persistent (n=4) atrial fibrillation. INTERVENTIONS. Pulmonary vein isolation by ablation with a 28-mm cryoballoon catheter. MAIN OUTCOME MEASURES. Safety, effectiveness, and learning curve of this procedure. RESULTS. Of 67 pulmonary veins, 61 (91%) could be successfully isolated with the cryoballoon alone. The remaining pulmonary veins were isolated with additional ablation using an 8-mm tip cryocatheter. One phrenic nerve palsy developed during right middle pulmonary vein ablation, which resolved. Another patient endured a minor guidewire dissection of the right inferior pulmonary vein. The mean (standard deviation) procedural and fluoroscopic times were 231 (32) and 62 (18) minutes, respectively. On comparing the first nine and last seven procedures, there was a significant improvement in procedural time (mean [standard deviation], 244 [32] vs 213 [24] minutes; P=0.04) and in the fluoroscopic time (70 [21] vs 51 [7] minutes; P=0.038). With a median follow-up of 21 months, nine (75%) of the 12 patients with paroxysmal atrial fibrillation and one (25%) of those four with persistent atrial fibrillation had no recurrence, without the use of anti-arrhythmic drugs. CONCLUSIONS. Pulmonary vein isolation by cryoballoon catheter ablation is safe and effective in treating patients with paroxysmal, but not for patients with persistent atrial fibrillation. A relatively short learning curve of around 10 cases was deemed appropriate.

Determination of total 14C residues of sarafloxacin in eggs of laying hens

[14C]sarafloxacin was orally administered to six laying hens for five consecutive days. Eggs were collected for 15 days after the initial drug treatment. Egg yolk and egg albumen were separated and assayed for total radioactive residues (TRR) using a combustion oxidizer and scintillation counting techniques. Radioactivity was detected in egg yolk and egg albumen on the second day of dosing and reached a maximum at 24 h after drug withdrawal. Thereafter, the sarafloxacin TRR levels in egg albumen declined rapidly and were undetectable 2 days after the last dose, whereas the levels in egg yolk declined at a much slower rate and were undetectable 7 days after drug withdrawal. In both the egg albumen and yolk, HPLC analysis indicated that the parent sarafloxacin was the major component.

Distribution of total 14C residue in egg yolk, albumen, and tissues following oral [14C]sulfamethazine administration to hens

The distribution of total 14C residues was studied in egg yolk and albumen after administration of either single or multiple oral dosages of [14C]sulfamethazine (SMZ). One day after a single dose of [14C]SMZ (121 mg of sulfamethazine, 2.42 x 10(7) dpm), the 14C residue concentration peaked in egg albumen and egg yolk with the concentration in the former >4-fold greater than in the latter. Three days postdose, the 14C residue concentration in the yolk was approximately 7-fold higher than in the egg albumen. A multiple dose of [14C]SMZ containing sulfamethazine mass equivalent of an average therapeutic dose (282 mg, 2.9 x 10(7) dpm) for chickens was also administered orally for six consecutive days to hens. A significantly reduced level of egg production was observed during the medication, and most of the hens stopped laying eggs after the last dose. The 14C residue concentrations peaked on the last day (sixth) of medication in egg albumen and yolk. The 14C residue concentrations were also measured in liver, muscle, blood, and plasma of chickens sacrificed at 1, 24, 48, and 72 h after the last dose. Highest concentrations of 14C residue were accumulated in liver followed by, in decreasing order, blood, plasma, and muscle.

Creamatocrit and the nutrient composition of human milk

OBJECTIVE

We tested the hypothesis that creamatocrit, the length of the cream column separated from milk by centrifugation and expressed as a percentage of the length of the total milk column, is a useful measure of the lipid concentration and the energy content of human milk.

STUDY DESIGN

Milk samples from 17 mothers of preterm infants were analyzed prospectively, fresh as well as frozen and thawed, for creamatocrit measurement and nutrient composition.

RESULTS

Creamatocrit correlated strongly with lipid concentration and energy content of human milk, fresh or frozen and thawed. The energy content can be calculated from the regression equation: Energy (kcal/dl) = 5.99 x creamatocrit(%) + 32.5 for a fresh sample, and energy (kcal/dl) = 6.20 x creamatocrit(%) + 35.1 for a frozen sample.

CONCLUSION

Calculations of energy content from the creamatocrit measurement may be useful for an accurate assessment of energy intake in preterm infants fed human milk.

Determination of cephapirin and ceftiofur residues in bovine milk by liquid chromatography with ultraviolet detection

A method capable of quantitating cephapirin at a level fo 20 ng/mL and ceftiofur at a level of 50 ng/mL was developed for raw bovine milk. Raw bovine milk is deproteinated with acetonitrile. The supernatant is collected and then acetonitrile is removed under reduced pressure while warming in a water bath at 40 degrees-50 degrees C. The extract is mixed with water and loaded onto a conditioned C18 solid-phase extraction column. Analytes are eluted with acetonitrile, which is removed completely under a stream of nitrogen gas. Analytes are separated from coextractives by gradient elution with an ion-pair mobile phase on a reversed-phase column and are detected by ultraviolet absorbance at 290 nm. Mean recoveries from fortified milk samples ranged from 79 to 87% for cephapirin and from 76 to 86% for ceftiofur, with intralaboratory coefficients of variation ranging of 6-10% and 7-14%, respectively.

The nutritional response to trauma in older people

Physiological changes affecting the digestive system in old age may mean that older people have a higher risk of malnutrition as a result of physical trauma. The findings showed that the nutritional status of older subjects who had undergone total hip replacement did not correlate with age. The study indicated that people over the age of 75 may have a tendency of develop postoperative complications, which could be affected by malnutrition.

Determination of albendazole-2-aminosulfone in bovine milk using high-performance liquid chromatography with fluorometric detection

An analytical method for the determination of albendazole (ABZ) residues in bovine milk was developed using one of its major metabolites, albendazole-2-aminosulfone (ABZ2NH2) as the marker. The method involved acid hydrolysis of milk followed by liquid-liquid extraction and solid-liquid phase clean-up of the extract. A reversed-phase HPLC with fluorometric detection was used to quantitate the marker residue. The method exhibited a high degree of precision and good accuracy as demonstrated by a relative standard deviation (R.S.D.) < 5% for the replicate analyses and 91.8 to 104.1% recovery of the fortification level (25-200 ng/ml), respectively. The ratio of the concentrations of the marker and total residues in milk over a 36-120 h withdrawal period was found to be steady at 43.1 indicating a definite relationship between the marker and the total residues of ABZ. The analytical method was used successfully to determine total residues in milk of cattle treated with ABZ.

In vivo metabolism of retrorsine and retrorsine-N-oxide

The in vivo metabolism and excretion of the urinary metabolites from the pyrrolizidine alkaloids (PAs), retrorsine (RET) and retrorsine-N-oxide (RET-NO) have been studied in rats. Isatinecic acid (INA), pyrrolic metabolites, N-oxides and retronecine accounted for 31.0, 10.3, 10.8 and 0.39% of the administered RET. Predosing rats with triorthocresyl phosphate (TOCP), had no effect on the excretion of pyrrolic metabolites and INA. Phenobarbital (PB) increased the excretion of both pyrrolic metabolites and INA with a corresponding decrease in the excretion of RET and N-oxides; the retronecine levels remained unaltered. When RET-NO was administered i.p., the urinary levels of pyrrolic metabolites, INA and RET were decreased relative to those treated with RET. The p.o. administration of RET-NO produced significantly higher levels of pyrrolic metabolites, INA and RET. These results suggest that esterase hydrolysis plays a minor role in the formation of INA and that a common metabolic pathway may exist between pyrrolic metabolites and INA formation.

Synthesis of alkoxy-substituted diaryl compounds and correlation of ring separation with inhibition of tubulin polymerization: differential enhancement of inhibitory effects under suboptimal polymerization reaction conditions

A number of cytostatic compounds (2-4, 7, and 8), which can be described as "diaryl", inhibit tubulin polymerization, cause cells to accumulate in mitotic arrest, and competitively inhibit the binding of colchicine to tubulin. They differ, however, in the separation of the two aryl moieties. To attempt to understand this variability we prepared a series of analogues modeled on 3 and 4 ("benzodioxole series") and on 7 and 8 ("combretastatin series") which differed only in the number of methylene units (ranging from none to four) separating the aryl moieties. These compounds were evaluated for their effects on tubulin polymerization, colchicine binding, and the growth of L1210 murine leukemia cells. In terms of inhibitory effects on tubulin polymerization, for the combretastatin series there was an optimal separation of the two phenyl rings by a two-carbon bridge (compound 24), with progressively decreasing inhibitory activity when the separation was by one carbon (20), three carbons (25), or four carbons (28) (the biphenyl analogue 16 was inactive). The benzodioxole series, however, did not permit us to generalize this finding, because the least active agents prepared (39 and 40) had a two-carbon bridge, while those with one- (5 and 6) and three-carbon (46 and 47) bridges were nearly equivalent in potency. Submicromolar IC50 values for inhibition of L1210 cell growth were only obtained for compounds 20 (IC50, 0.2 microM), 24 (0.07 microM), and 25 (0.4 microM). While evaluating the effects of these agents on tubulin polymerization, we noted with the combretastatin series and with several standard agents that apparent potency (in terms of IC50 values) was always lower if the reaction was performed at 30 degrees C, with 0.25 mM MgCl2, than at 37 degrees C, with 1.0 mM MgCl2. This enhancement of IC50 values in the former system as compared with the latter was particularly dramatic for the less active agents (e.g., 28) as compared with the more active (e.g. 24).

Species difference in the urinary excretion of isatinecic acid from the pyrrolizidine alkaloid retrorsine

1. The urinary excretion of the metabolites, isatinecic acid and pyrrolic metabolites from the pyrrolizidine alkaloid retrosine were lower in the resistant species, guinea-pigs, than the susceptible species, mice, hamsters and rats. 2. The urinary N-oxides levels, however, were higher in guinea-pigs relative to mice, hamsters and rats. 3. These results conform to the postulate that a common metabolic pathway exists between the formation of isatinecic acid and pyrrolic metabolites. 4. The resistance of guinea-pigs to PA poisoning is attributed to the high metabolism of PAs to N-oxides combined with a corresponding low conversion to pyrrolic metabolites.

Trilostane with hydrocortisone in treatment of metastatic breast cancer

Twenty-six patients with metastatic breast cancer who had previously responded to one or more endocrine therapies participated in a clinical trial of the combination of trilostane and hydrocortisone for subsequent disease progression. Of these, one patient achieved complete remission (4%), and five had partial response (19%). The median time to progression from initiation of therapy for responding patients was six months (range: 4 - 32 + months). Major toxicities included nausea/vomiting (16 patients), facial flushing (14), abdominal cramping (11), and oral paresthesia (10). Therapy was discontinued in four patients (15%) because of drug intolerance. Fourteen patients who failed trilostane were treated with aminoglutethimide and hydrocortisone. Six patients showed objective response (PR + MR). These data show that trilostane and hydrocortisone in combination can produce an objective response in a significant fraction of patients and that the combination has a different spectrum of toxicity from aminoglutethimide/hydrocortisone. A small number of patients crossed over to aminoglutethimide showed a few objective responses, suggesting a partial lack of cross-resistance between the two antiadrenal drugs.

Interactions of tubulin with potent natural and synthetic analogs of the antimitotic agent combretastatin: a structure-activity study

Combretastatin, an antineoplastic and antimitotic agent, was isolated from the bark of Combretum caffrum [Can. J. Chem. 60: 1374-1376 (1982); Biochem. Pharmacol. 32:3864-3867 (1983)]. Structurally, combretastatin consists of two substituted benzene rings linked by a saturated, hydroxy-substituted two-carbon bridge. A large number of combretastatin analogs have now been synthesized or obtained from C. caffrum. These vary in substituents on the phenyl rings or bridge carbons, bridge length, unsaturation of the bridge (i.e., stilbene derivatives, with the two phenyl rings oriented either cis or trans), and in precise ring structure (two major variants, with the bridge incorporated into a third six-member ring to form a phenanthrene structure or a methyl group eliminated from vicinal methoxy substituents to form a benzodioxole ring). Available analogs (17 natural products and 22 synthetic agents) were examined for antimitotic and cytotoxic activity and for effects on tubulin polymerization and colchicine binding. Nineteen compounds inhibited cell growth by 50% or more at concentrations of 1 microM or less, and 14 inhibited tubulin polymerization by at least 50% at stoichiometric drug concentrations. The most potent cytotoxic agents generally strongly inhibited both tubulin polymerization and the binding of colchicine to tubulin. The most promising compound is the (cis)-stilbene derivative (cis)-1-(3,4,5-trimethoxyphenyl)-2-(3'-hydroxy-4'-methoxyphenyl)ethene, which has been named combretastatin A-4. This compound inhibited cell growth by 50% at 7 nM, inhibited tubulin polymerization by 50% at 2.5 microM (1/4 molar equivalent), and competitively inhibited colchicine binding with an apparent Ki of 0.14 microM.

Synthesis and nephrotoxicity of 6-bromo-2,5-dihydroxy-thiophenol

The formation of potentially reactive thiols has been postulated to play a role in the nephrotoxicity caused by a number of glutathione and/or cysteine conjugates. However, the inherent reactivity of such compounds has precluded both their identification in biological systems and a determination of their actual toxicity. To this end we have synthesized 6-bromo-2,5-dihydroxy-thiophenol as a putative metabolite of nephrotoxic 2-bromohydroquinone-glutathione conjugates. The compound was prepared by the addition of sodium thiosulfate to 2-bromo-1,4-benzoquinone followed by reduction of the S-arylthiosulfate to the thiophenol. 2,5-Dihydroxy-thiophenol was similarly prepared. Structural identification was confirmed by mass spectroscopy and nuclear magnetic resonance spectroscopy. Administration of 6-bromo-2,5-dihydroxy-thiophenol to rats (0.35 mmol/kg; intraperitoneally) caused an increase in blood urea nitrogen and histological alterations similar to those observed after 2-bromo-(diglutathion-S-yl)hydroquinone administration. 2,5-Dihydroxy-thiophenol was also nephrotoxic but at a dose of 0.6 mmol/kg. In contrast, no effects on liver pathology were observed after administration of either 6-bromo-2,5-dihydroxy-thiophenol or 2,5-dihydroxy-thiophenol and serum glutamate pyruvate transaminase levels were normal. Neither 2-, 3-, nor 4-bromothiophenol had any effect on blood urea nitrogen at doses between 0.2 and 0.8 mmol/kg (intraperitoneally) and no apparent alterations were seen in kidney slices prepared from bromothiophenol-treated rats. These findings suggest that the quinone function of 6-bromo-2,5-dihydroxy-thiophenol is necessary for the expression of toxicity. In this respect, the lower activity of NAD(P)H quinone oxidoreductase (EC 1.6.99.2) in renal cortex may be of toxicological significance.